66644111 has 2 divisors, whose sum is σ = 66644112. Its totient is φ = 66644110.

The previous prime is 66644093. The next prime is 66644113. The reversal of 66644111 is 11144666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66644111 - 2¹⁸ = 66381967 is a prime.

It is a Sophie Germain prime.

Together with 66644113, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66644113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33322055 + 33322056.

It is an arithmetic number, because the mean of its divisors is an integer number (33322056).

Almost surely, 2^66644111 is an apocalyptic number.

66644111 is a deficient number, since it is larger than the sum of its proper divisors (1).

66644111 is an equidigital number, since it uses as much as digits as its factorization.

66644111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 29.

The square root of 66644111 is about 8163.5844455729. The cubic root of 66644111 is about 405.4343985064.

Adding to 66644111 its reverse (11144666), we get a palindrome (77788777).

The spelling of 66644111 in words is "sixty-six million, six hundred forty-four thousand, one hundred eleven".